Fix few shadow warnings (#4409)

- declaration of ‘memidx’ shadows a previous local
- declaration of ‘count’ shadows a previous local

core/iwasm/interpreter/wasm_interp_classic.c

@@ -4088,7 +4088,7 @@ wasm_interp_call_func_bytecode(WASMModuleInstance *module,
                     case WASM_OP_STRING_ENCODE_LOSSY_UTF8_ARRAY:
                     case WASM_OP_STRING_ENCODE_WTF8_ARRAY:
                     {
-                        uint32 start, array_len, count;
+                        uint32 start, array_len;
                         int32 bytes_written;
                         EncodingFlag flag = WTF8;
                         WASMArrayType *array_type;

core/iwasm/interpreter/wasm_loader.c

@@ -15024,8 +15024,6 @@ re_scan:
                     case WASM_OP_STRING_NEW_LOSSY_UTF8:
                     case WASM_OP_STRING_NEW_WTF8:
                     {
-                        uint32 memidx;
-
 #if WASM_ENABLE_JIT != 0 || WASM_ENABLE_WAMR_COMPILER != 0
                         func->has_memory_operations = true;
 #endif
@@ -15037,7 +15035,6 @@ re_scan:
                         POP_I32();
                         POP_I32();
                         PUSH_REF(REF_TYPE_STRINGREF);
-                        (void)memidx;
                         break;
                     }
                     case WASM_OP_STRING_CONST:
@@ -15065,8 +15062,6 @@ re_scan:
                     case WASM_OP_STRING_ENCODE_LOSSY_UTF8:
                     case WASM_OP_STRING_ENCODE_WTF8:
                     {
-                        uint32 memidx;
-
 #if WASM_ENABLE_JIT != 0 || WASM_ENABLE_WAMR_COMPILER != 0
                         func->has_memory_operations = true;
 #endif
@@ -15078,7 +15073,6 @@ re_scan:
                         POP_I32();
                         POP_STRINGREF();
                         PUSH_I32();
-                        (void)memidx;
                         break;
                     }
                     case WASM_OP_STRING_CONCAT:
@@ -15119,8 +15113,6 @@ re_scan:
                     case WASM_OP_STRINGVIEW_WTF8_ENCODE_LOSSY_UTF8:
                     case WASM_OP_STRINGVIEW_WTF8_ENCODE_WTF8:
                     {
-                        uint32 memidx;
-
 #if WASM_ENABLE_JIT != 0 || WASM_ENABLE_WAMR_COMPILER != 0
                         func->has_memory_operations = true;
 #endif
@@ -15135,7 +15127,6 @@ re_scan:
                         POP_REF(REF_TYPE_STRINGVIEWWTF8);
                         PUSH_I32();
                         PUSH_I32();
-                        (void)memidx;
                         break;
                     }
                     case WASM_OP_STRINGVIEW_WTF8_SLICE:
@@ -15167,8 +15158,6 @@ re_scan:
                     }
                     case WASM_OP_STRINGVIEW_WTF16_ENCODE:
                     {
-                        uint32 memidx;
-
 #if WASM_ENABLE_JIT != 0 || WASM_ENABLE_WAMR_COMPILER != 0
                         func->has_memory_operations = true;
 #endif
@@ -15182,7 +15171,6 @@ re_scan:
                         POP_I32();
                         POP_REF(REF_TYPE_STRINGVIEWWTF16);
                         PUSH_I32();
-                        (void)memidx;
                         break;
                     }
                     case WASM_OP_STRINGVIEW_WTF16_SLICE: